The case open, both radiator wings unfolded beside the center

Folding PC Case

A water-cooled Mini-ITX case that folds in three, designed to fit dual 360 mm radiators in ~9 L.

CAD model Design breakdown

Case volume: ~9 L
Radiators: 2 × 360 mm
Cooling capacity: ~1,100 W est.

Folding PC CaseThe case open, isometric

1 / 10

Properties

AssemblyDesigned

Folding PC Case

A water-cooled Mini-ITX case that folds in three, designed to fit dual 360 mm radiators in ~9 L.

Popular cases with this much cooling take up 26.3-50 L.

My goal was to fit that cooling into something much smaller, without making the hardware hard to reach. Folding solves both problems. The case is compact when it’s closed and fully accessible when it’s open.

Key figures
Size, closed	195 × 400 × 115 mm
Case volume	~9 L
Radiators	2 × 360 mm
Cooling capacity	~1,100 W est.

PartOff the shelf

ASUS ROG Strix X870-I

Mini-ITX. Cooled by the custom CPU monoblock.

Main system
Motherboard	ASUS ROG Strix X870-I Gaming WiFi
CPU	AMD Ryzen 9 9950X3D
RAM	96 GB DDR5-6000 CL28
Storage	4 TB Crucial T705, PCIe Gen5 NVMe

PartOff the shelf

Laing DDC 4.2 PWM pumps

Two pumps in series, beside the RTX 5090.

Pumps
Model	Laing DDC 4.2 PWM
Count	2
Voltage	12 V
Max power, each	20 W
Speed	1,000-4,500 rpm
Max flow, each	517 L/h
Max head	4.34 m
Arrangement	In series

01Built to travel

Inspiration

A full-power, water-cooled PC that folds shut for the flight, then opens up so it never has to compromise on cooling.

The problem
Traveling often, and flying especially, with a high-performance PC means shipping it or trusting baggage handling. A small case fixes that, but water-cooling a small case always means a compromise.
The usual compromise
Small builds stack their radiators, so one breathes the other’s exhaust, or use one thick radiator, which can’t match two thin ones on fresh air at quiet fan speeds. Something always gives: thermals, performance or noise.
The fold
For travel, the wings fold in and lock. Set up, they swing out so each radiator pulls its own fresh air: nothing stacked, no recycled heat, and a quieter build.

02Size

Cooling per liter

~9 L for an estimated ~1,100 W of cooling: ~122 W per liter.

Case	Volume	Cooling, est.	Cooling per liter, est.
Folding PC Case	~9 L	~1,100 W	122 W/L
Lian Li A3-mATX	26.3 L	~1,100 W	42 W/L
HYTE Y40	50 L	~1,050 W	21 W/L
Lian Li O11 Dynamic Mini V2	45.4 L	~900 W	20 W/L
Fractal Design North	42 L	~800 W	19 W/L
Lian Li Lancool 216	~55.6 L	~800 W	14 W/L

03Mechanism

How it folds

Three sections: a center backplate for the components, and a radiator wing on each side.

Closed: The radiators become the outer walls, and everything inside is protected.
The linkage: Two hinges with a slider between them, not one hinge, so each wing can wrap around the center and sit flush.
Open: Each wing can lie flat, stand upright or sit anywhere between, closer to or farther from the center, so the case fits the space it’s in.

The whole case, open to closed

One linkage, open to closed

04Every millimeter counts

Materials

The 3 mm backplate carries nearly everything, and both ~1.2 kg wings hang off it. Every millimeter counts, so each part has to be strong and stiff at its minimum thickness, under 2-3 g handling loads.

Backplate

3 mm thick

Carbon fiberA wide, flat panel loaded in bending: for its weight, carbon is far stiffer than aluminum or titanium. Bonded inserts take the fasteners.

G10 fiberglassIsolates the boards from the conductive carbon and stops galvanic corrosion. A ground strap grounds the chassis.

Hinges

~2.2-2.5 mm arms

Grade 5 titanium, Ti-6Al-4VThe hinges carry each wing through arms only ~2.2-2.5 mm thick. Grade 5 titanium yields at roughly three times the stress of 6061 aluminum, so a thin arm stays strong (FEA to confirm), and threads tap straight into it, saving the room inserts would take.

SteelTitanium galls against itself when parts slide, so every bearing, pin and bushing is steel.

Wing frames

~1.2 kg per wing

TitaniumEach frame is an open shape that wraps the radiator, takes the knuckle bearing loads and twists when a wing is lifted. Carbon fiber can’t be bent into flanges or take point loads like that; titanium can. Bent flanges and ribs add stiffness without thickness, and the bolted-in radiator stiffens the frame further.

One wing, 1.2 kgRadiator ~0.65 kg + three fans ~0.26 kg leaves ~0.29 kg for the titanium frame and hinges.
Hinge loadAt 3 g, a wing pulls ~35 N on its hinges, through arms 2.2-2.5 mm thick.
Why titanium thereTi-6Al-4V yields at ~880 MPa, about 3.2× 6061 aluminum’s ~276 MPa, for 1.6× the weight.

3.8×The same panel, three materialsCarbon fiber is 3.8× stiffer than aluminum at the same weight. See the comparison

The center backplate is about 400 × 190 × 3 mm (228 cm³), estimated from the closed case’s 195 × 400 × 115 mm. The same panel in each material:

Material	Density	Panel weight	Stiffness, same thickness	Stiffness, same weight
Carbon fiber	1.55 g/cm³	0.35 kg	0.72×	3.8×
Aluminum 6061-T6	2.70 g/cm³	0.62 kg	1.00×	1.0×
Titanium Ti-6Al-4V	4.43 g/cm³	1.01 kg	1.65×	0.4×

Stiffness relative to aluminum. Bending stiffness scales with E·t³; at equal weight the thickness scales with 1/ρ, so it goes with E/ρ³. Moduli: carbon laminate ~50 GPa in-plane, aluminum 69 GPa, titanium 114 GPa.

05The estimate

Cooling

Each wing carries a radiator and its fans. Two Laing DDC pumps move the coolant through flexible tubing that folds with the wings, and every major heat source is water-cooled.

Heat in, stock~1,000 W

Loop can shed, sustained~1,100 W est.

Short peaks1,300-1,400 W

RTX 5090 ~575 W
CPU ~200 W
RTX 5060 ~145 W
LattePanda Mu Ultra ~30 W
Pumps 40 W

Estimates.

Thermal calculations

Coolant over room airΔT = Q / UA = 1,100 W ÷ 30-35 W/°C31-37 °C, so about 56-62 °C coolant in a 25 °C room.
Warming across the loopΔT = Q / (ṁ·c) = 1,100 W ÷ (0.063 kg/s × 4,186)4.2 °C from the coldest point to the hottest, at 3.75 L/min.
A short peak250 W extra ÷ (0.37 kg × 4,186)0.16 °C per second, counting only the reservoir’s water: about 6 s per degree. The rest of the coolant and the copper slow it further.

Can two thin radiators handle it? The test data

Need
The pumps are rated for coolant up to 60 °C: a 35 °C budget in a 25 °C room. 1,100 W across 35 °C needs 31.4 W/°C: 15.7 W/°C per radiator.
Test
TechPowerUp tested this exact radiator, the XSPC TX360, at 1 GPM in a 25 °C chamber, on a 550 W overclocked system.
Check
At 800 rpm, with less airflow than a P12 Slim, the coolant sat 14.7 °C above the air. Falling short would mean under 231 W reached the loop: less than half the system’s draw. One TX360 covers its half with margin.

One XSPC TX360, tested by TechPowerUpCoolant above room air, in °C, at each fan speed. Shorter is better.

16.2600
14.7800
11.751,200
9.31,500
8.351,800
7.552,000
7.32,200

Fan speed, rpm

Sources and method

At 800 rpm the test fan is rated 57.3 m³/h; a P12 Slim at full speed, 71.5 m³/h. TechPowerUp used 25 mm Noiseblocker eLoop fans and the P12 Slim is 15 mm, so the two are compared by rated airflow only. Sources: TechPowerUp, XSPC TX360 review: thermal performance; Alphacool, Laing DDC pump: water 10-60 °C; Aqua Computer, Noiseblocker eLoop B12-1: 800 rpm, 57.3 m³/h; Aquatuning, Arctic P12 Slim PWM PST: 2,100 rpm, 71.53 m³/h.

Cooling parts: radiators, fans, pumps, reservoir and loop

Radiators
Model	XSPC TX360 ultra-thin
Count	2
Size	125 × 20.5 × 398 mm
Core	16 mm
Fin density	22 FPI
Material	Copper and brass
Fans
Model	Arctic P12 Slim
Count	6
Per radiator	3
Thickness	15 mm
Max speed	2,100 rpm
Airflow, each	71.5 m³/h

Pumps
Model	Laing DDC 4.2 PWM
Count	2
Voltage	12 V
Max power, each	20 W
Speed	1,000-4,500 rpm
Max flow, each	517 L/h
Max head	4.34 m
Arrangement	In series
Reservoir
Outside	340 × 47 × 33 mm
Wall	3 mm
Inside volume	~370 mL
Loop
Layout	One series loop
Order	Reservoir → pumps → RTX 5090 → LattePanda Mu Ultra → RTX 5060 → right radiator → CPU → left radiator
Flow, operating	~3.5-4 L/min
Restriction, whole loop	~1.08 bar
Pumps, deadhead in series	~1.15 bar
Flow sensor	Hard shutdown on low flow
Tubing	Flexible
Through-board tube, OD / ID	4.5 / 3.5 mm
Through-board tube	Copper, PTFE sleeve

06Cooling

Waterblocks

Every major heat source is water-cooled. The radiators are on the wings, so all of the heat has to get into the loop to reach them.

In progress. The CPU monoblock is the first block, and it’s still being designed. Every screenshot in this section is of the monoblock.

Fully dimensioned

(opens full size)
The whole channel sketch
(opens full size)
Close-up 1
(opens full size)
Close-up 2
(opens full size)
Close-up 3
(opens full size)
Close-up 4
(opens full size)
Close-up 5

The numbers behind it

Split the flow
v = Q / A · Dₕ = 4A / P
At 3.75 L/min, one 4.0 × 3.5 mm channel would run at 4.5 m/s. Two branches carry half each: 2.2 m/s, Dₕ 3.7 mm. The 6.0 × 3.5 mm trunk takes the full flow at 3.0 m/s, Dₕ 4.4 mm. Re ≈ 9,000-15,000: turbulent throughout.
Velocity squared
ΔP = (f·L/Dₕ + ΣK) · ρv²/2
Halving the velocity cuts each velocity head (ρv²/2) to a quarter: ~2.5 kPa in a branch against ~10 kPa in a single channel. Block total: ~0.38 bar.
Bend radii
K(sharp 90°) ≈ 1.1 → K(r/Dₕ ≈ 1) ≈ 0.3
Minor losses dominate at these velocities. An R4 centerline on the branches and R6 on the trunk (R2 / R3 inner) cut the first estimate of 0.7 bar nearly in half, with no change in channel size.
Jet plate
A = 25 × 0.475 mm → v ≈ 5.3 m/s, ρv²/2 ≈ 0.14 bar
The single slot fires coolant onto the microfins at about two velocity heads: ~0.3 bar. The block’s biggest restriction, on purpose: pressure traded for heat transfer.
Gap cubed
Q_bypass = w·h³·ΔP / (12·μ·L)
Leakage around the jet plate goes with the gap cubed. At the 0.1 mm target, a 0.05 mm error changes bypass 8×, so the Ni-P plating (10-12 µm) is in the tolerance stack and the slots are cut oversized.
Operating point
ΔP_pumps(Q) = ΔP_loop(Q)
Two DDCs in series add their heads: ~1.15 bar at zero flow, against ~1.08 bar for the whole loop at ~3.5-4 L/min. One pump alone deadheads near ~0.58 bar, below the loop’s restriction, so it would barely move coolant. The second pump carries load, and a flow sensor with a hard shutdown is required.

Each block, and how the monoblock is made

The blocks
CPU monoblock	C145 copper under an acrylic top, with split-and-merge channels and a brass jet plate over the CPU.
RTX 5090	The largest heat source, at ~575 W stock. A pedestal inside the Founders Edition’s brace window bridges ~1.0-1.2 mm from the GDDR7 tops to the die.
RTX 5060	The secondary system’s GPU, at ~145 W stock.
LattePanda Mu Ultra	The secondary system’s compute module, at ~30 W stock.

How the monoblock is made
Design	Modeled in SolidWorks.
Body	C145 tellurium copper, under a cast acrylic (PMMA) top.
Plating	Electroless nickel (Ni-P) per ASTM B733, mid-phos, 10-12 µm.
Channels	Split and merge: two 4.0 × 3.5 mm branches into a 6.0 × 3.5 mm trunk, 6.5 mm block, ~7.5-8 mm at the port boss.
Jet plate	C360 brass, cut by wire EDM. A three-piece stack with a swappable 0.58 mm spacer sets a 0.10 mm standoff gap.
Seal	A 2.0 mm O-ring cord in a 2.70 × 1.50 mm groove. M3 A2 stainless screws with nylon washers sit outboard of the seal.
Thermal interface	Thermal Grizzly KryoSheet on the CPU and GPU, Laird Tflex pads elsewhere.

07Hardware

Two computers, one case

The main system sits on the center section. On the inner right, a LattePanda Mu Ultra (Intel Core Ultra 7 256V) with a low-profile RTX 5060 runs alongside it.

Main

Rendering, work and simulation

Motherboard: ASUS ROG Strix X870-I Gaming WiFi
CPU: AMD Ryzen 9 9950X3D
RAM: 96 GB DDR5-6000 CL28
GPU: NVIDIA RTX 5090 Founders Edition, on a riser
Storage: 4 TB Crucial T705, PCIe Gen5 NVMe

Secondary

System monitoring · Remote access · Offloading compute

Compute module: LattePanda Mu Ultra
CPU: Intel Core Ultra 7 256V
GPU: ZOTAC GAMING GeForce RTX 5060 Low Profile
GPU memory: 8 GB GDDR7
GPU size: 182.5 × 69 × 38.2 mm

(opens full size)
Secondary system, rendered
(opens full size)
Inner right, in CAD

Custom carrier board

Module: LattePanda Mu Ultra, 260-pin socket
GPU slot: PCIe 4.0 ×4, own 12 V
Power: 12 V from the second HDPLEX 800 W board
Storage: M.2 NVMe, M.2 Wi-Fi / Bluetooth
I/O: Gigabit Ethernet, 2 × USB 3.2 Gen 2, HDMI
Control: RP2040: 6 fans, 2 pumps, 6 RGB, 5 temperature sensors
Designed in: KiCad 10

Carrier board: full write-up →

(opens full size)
The carrier board's block diagram, from its own page

Power

Supply	External fanless AC-DC
Bus	48 V
Boards	2 × HDPLEX 800 W DC-ATX
Each, continuous / peak	720 W / 1,080 W
Each, size	170 × 90 × 31 mm
Input range	12-63 V
Board 1	RTX 5090
Board 2	Everything else
Board 2, load	~425-475 W

08Process

Iterations

Five versions over two years, from a case where nothing moved to the hinge, slider, hinge linkage it has now.

(opens full size)
(opens full size)
Version 1
Everything fixed in place; nothing moves. A top fan and a bottom fan push air out of the case, and six side fans pull air in through the radiators.
(opens full size)
(opens full size)
Version 2
Added a single hinge, so the radiators fold out. Each radiator gets its own fresh air, and no heat is trapped in a box.
(opens full size)
(opens full size)
Version 3
Added a slider: a hinge and a slider on each side. The structure can shrink when folded, for a smaller closed volume.
(opens full size)
(opens full size)
Version 4
Rethought the part layout and refined the case design, keeping the hinge and slider.
(opens full size)
(opens full size)
Version 5Current
Added a second hinge: hinge, slider, hinge. Closed, the wings wrap the center and sit flush; open, they can take almost any position. The current design.

09Process

Tools

Case development began in Onshape. With the waterblocks, the work moved to SolidWorks, where simulation drives the design. Blender handles visualization and design studies of the case.

(opens full size)
Case designThe case, from first concept to the full assembly.
(opens full size)
Waterblocks and simulationWaterblock design, with simulation alongside the CAD.
(opens full size)
VisualizationRenders, the fold animation and design studies of the case.

10Blender

Renders

(opens full size)
Inner hinge
(opens full size)
Ghost carbon backplate
(opens full size)
Fan and radiator
(opens full size)
Coolant tank
(opens full size)
RTX 5060 and LattePanda Mu Ultra
(opens full size)
Motherboard
(opens full size)
CPU heatspreader
(opens full size)
GB202 die
(opens full size)
RTX 5090 board

11Reference

Full specs

Case and structure

Case

Form	Folding, three sections plus two wings
Sections	Center, inner left, inner right, left wing, right wing
Size, closed	195 × 400 × 115 mm
Volume, closed	~9 L
Airflow	In through the front, out the back
Front I/O	Every internal header on the X870-I
Motherboard size	Mini-ITX
CAD	Onshape (case), SolidWorks (waterblocks, simulation)
Visualization	Blender

Structure

Backplate	Carbon fiber
Backplate thickness	3 mm
Component-side ply	G10 fiberglass
Inserts	Bonded titanium or stainless steel
Finish	Matte carbon, black-tinted satin clearcoat
Hinge arms, knuckles, sliders	Grade 5 titanium, Ti-6Al-4V
Hinge arm thickness, target	~2.2-2.5 mm
Moving contacts	Steel bearings, pins or bushings
Wing frames	Titanium
Grounding	Dedicated chassis ground strap
Wing mass	~1.2 kg

Cooling loop

Radiators

Model	XSPC TX360 ultra-thin
Count	2
Size	125 × 20.5 × 398 mm
Core	16 mm
Fin density	22 FPI
Material	Copper and brass

Fans

Model	Arctic P12 Slim
Count	6
Per radiator	3
Thickness	15 mm
Max speed	2,100 rpm
Airflow, each	71.5 m³/h

Pumps

Model	Laing DDC 4.2 PWM
Count	2
Voltage	12 V
Max power, each	20 W
Speed	1,000-4,500 rpm
Max flow, each	517 L/h
Max head	4.34 m
Arrangement	In series
Max pressure	0.4 bar
Size	91 × 70 × 40 mm
Weight, each	220 g

Reservoir

Outside	340 × 47 × 33 mm
Wall	3 mm
Inside volume	~370 mL

Loop

Layout	One series loop
Order	Reservoir → pumps → RTX 5090 → LattePanda Mu Ultra → RTX 5060 → right radiator → CPU → left radiator
Flow, operating	~3.5-4 L/min
Restriction, whole loop	~1.08 bar
Pumps, deadhead in series	~1.15 bar
Flow sensor	Hard shutdown on low flow
Tubing	Flexible
Through-board tube, OD / ID	4.5 / 3.5 mm
Through-board tube	Copper, PTFE sleeve

Cooling estimate

Stock heat load

RTX 5090	~575 W
CPU	~200 W
RTX 5060	~145 W
LattePanda Mu Ultra	~30 W
Pumps	40 W
Total	~1,000 W

Cooling estimate

Radiator capacity, both at full fan speed	~30-35 W/°C
Short peaks, absorbed by the loop’s thermal mass	1,300-1,400 W
Sustained capacity	~1,100 W est.

Waterblocks

CPU monoblock

Status	In progress
Designed in	SolidWorks
Body	C145 tellurium copper, cast acrylic top
Plating	Ni-P, ASTM B733 mid-phos, 10-12 µm
Thickness	6.5 mm, ~7.5-8 mm at the port boss
Channels	Two 4.0 × 3.5 mm branches into a 6.0 × 3.5 mm trunk
Bends	R4 centerline on the branches, R6 on the trunk (R2 / R3 inner)
Jet plate	C360 brass, cut by wire EDM
Jet	One 25 × 0.475 mm slot, 0.10 mm standoff
Jet stack	Three pieces, swappable 0.58 mm spacer
Jet slots	Cut oversized to allow for the plating
Seal	2.0 mm O-ring in a 2.70 × 1.50 mm groove
Fasteners	M3 A2 stainless, nylon washers
Pressure drop, block	~0.38 bar
Pressure drop, jet plate	~0.3 bar
First estimate, block	0.7 bar

RTX 5090 block

Status	In progress
Card	Founders Edition
Design	Pedestal inside the card’s brace window
Pedestal bridge	~1.0-1.2 mm, GDDR7 tops to die

Thermal interface

CPU and GPU dies	Thermal Grizzly KryoSheet
Everything else	Laird Tflex HD700 / HD7.5 pads

Computers and power

Main system

Motherboard	ASUS ROG Strix X870-I Gaming WiFi
CPU	AMD Ryzen 9 9950X3D
RAM	96 GB DDR5-6000 CL28
GPU	NVIDIA RTX 5090 Founders Edition, on a riser
Storage	4 TB Crucial T705, PCIe Gen5 NVMe

Secondary system

Compute module	LattePanda Mu Ultra
CPU	Intel Core Ultra 7 256V
GPU	ZOTAC GAMING GeForce RTX 5060 Low Profile
GPU memory	8 GB GDDR7
GPU size	182.5 × 69 × 38.2 mm

Power (planned)

Supply	External fanless AC-DC
Bus	48 V
Boards	2 × HDPLEX 800 W DC-ATX
Each, continuous / peak	720 W / 1,080 W
Each, size	170 × 90 × 31 mm
Input range	12-63 V
Board 1	RTX 5090
Board 2	Everything else
Board 2, load	~425-475 W

Motherboard I/O

USB4 40Gbps, Type-C	2
USB 10Gbps	5 (4 Type-A, 1 Type-C)
USB 2.0	3
Video	HDMI
Network	Intel 2.5Gb Ethernet, Wi-Fi
Buttons	BIOS FlashBack, Clear CMOS
Internal USB	USB 10Gbps Type-C, USB 5Gbps header (2 ports), USB 2.0 headers (3 ports, on the ROG FPS card)
Internal other	2 × ARGB Gen 2, power button, front panel, thermal sensor
Fan headers	CPU fan, AIO pump, chassis fan
M.2	2 (PCIe 5.0 x4 and PCIe 4.0 x4)

Folding PC Case

Inspiration

Cooling per liter

How it folds

The whole case, open to closed

Materials

Backplate

Hinges

Wing frames

Cooling

Thermal calculations

Waterblocks

Fully dimensioned

The numbers behind it

Split the flow

Velocity squared

Bend radii

Jet plate

Gap cubed

Operating point

Two computers, one case

Rendering, work and simulation

System monitoring · Remote access · Offloading compute

Custom carrier board

Iterations

Tools

Renders

Full specs

Case and structure

Cooling loop

Cooling estimate

Waterblocks

Computers and power